The D.C. region is home to some of the nation’s largest road and rail projects. Many of them, such as the District’s 11th Street Bridge reconstruction, are progressing because they got money or approvals or both from the federal government.

The Transportation Department didn’t set any limits on the range of questions, but my suggestion is that we submit transportation questions that have local interest but would also be relevant to a national audience.

Please send questions to me at drgridlock@washpost.com. I’ll re­lay them to the Department of Transportation.

Closing on GW Parkway

The George Washington Parkway will temporarily close from Mount Vernon Circle to Little Hunting Bridge for the Woodrow Wilson Bridge Half Marathon from 6 to 11 a.m. Sunday. The ramps on this southern section of the parkway also will be closed.

The project, continuing through spring 2013, will rehabilitate the bridges over I-395 on H and K streets and Massachusetts Avenue NW. The bridge surfaces will be upgraded and improvements will be made to the drainage, traffic signals, street lighting and sidewalks. Some upgrades also will be made in the tunnel below the bridges to improve the lighting and air exchange.

Construction is scheduled for 9 a.m. and 4 p.m. weekdays and may also occur on weekends. At least one lane will be kept open in each direction on the bridges, and at least two lanes in each direction will be open in the tunnel.

Fairfax flood damage

The Virginia Department of Transportation is repairing roads and bridges across Fairfax County that have been closed because of the flooding from Tropical Storm Lee in early September.

The most recent rains haven’t helped, said Garrett Moore, VDOT’s district administrator for Northern Virginia. But by Friday, he expects Hunter Mill Road to reopen. Repairs to Carper’s Farm Way and Walker Road, which were damaged but not closed to traffic, will also be completed this week, he said.

VDOT said other roads and bridges closed by the storm should reopen by the end of October or mid-November.

D.C. Circulator changes

The District Department of Transportation is launching a series of changes Monday in the Circulator bus system. The Convention Center-Southwest Waterfront Circulator has ended. A new route will serve neighborhoods east of the Anacostia River for the first time, running from the Potomac Avenue Metrorail station to Skyland via Barracks Row (Eighth Street SE).

Buses on the Union Station-Navy Yard route will stop on Columbus Circle at the flag poles next to Union Station before turning right on F Street NE and right again on Second Street NE to reach Constitution Avenue. They no longer will stop inside the Union Station garage. On the Georgetown-Union Station and Dupont Circle-Georgetown-Rosslyn routes, some stops that are close together will be combined or eliminated.

For more transportation news, visit washingtonpost.com/transportation.